Technical Notes Archives | Edinburgh Instruments

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Technical Note: An Introduction to Flash Photolysis using the LP980 Spectrometer

In flash photolysis, a short pulse of light generates a transient (temporary) species in a sample; e.g. a radical intermediate or a short-lived excited state. As the sample relaxes back to the ground state or the final reaction products, the changes occurring are recorded as a function of time using a spectroscopic technique. A flash photolysis spectrometer typically monitors the change in absorption as a function of time, utilising a second light source (probe) besides the excitation (pump) pulse going through the sample. This technique is also known as transient absorption (TA). This technical note is aimed as an introduction to nanosecond flash photolysis for newcomers to the technique. We describe the operation of the LP980 spectrometer and show examples of measurements, with references to real-life applications.


Chromaticity Coordinates of Microcrystalline Phosphors

Luminescent materials used in lighting are standardized by the International Commission on Illumination (CIE). This standardisation is important for the lighting industry and is based on the illuminating conditions, the brightness and the observer. In this technical note, a series of phosphors emitting across the visible range were characterised in an FS5 Spectrofluorometer and their chromaticity coordinates calculated in its integrated software package, Fluoracle®.
FLS1000 FS5

Quenching of Fluorescence with Temperature

Reliable fluorescence standards and stable fluorescent probes for bio-analytics and chemistry are as important as sensitive indicator fluorophores that utilise the outstanding property of fluorescence of being highly sensitive to the fluorophore’s micro-environment. In this technical note we use the FS5 Spectrofluorometer to show the quenching of fluorescence with temperature. By using the extended capabilities of FS5-TCSPC we also record, for the same set of temperatures, the fluorescence lifetimes. We can show that temperature dependence of Rhodamine B is exclusively caused by dynamic quenching.

Transmission and Absorbance of Liquid Samples

The absorbance or optical density of a substance is inherent in all aspects of spectroscopy and follows the Beer-Lambert law. In this Technical Note, our FS5 Spectrofluorometer is equipped with a silicon detector that allows for transmission and absorbance measurements. After the transmission scans of the sample and reference are complete, they can be joined to calculate the absorbance through the absorption wizard in our operating software, Fluoracle.
FLS1000 FS5

Reflection, Absorption, Quantum Yield Measurements of Powder Samples Using the Integrating Sphere

Accurate Quantum Yield Measurements as well as precise measurements of the spectral dependence of reflection and/or absorption of powder samples, require an integrating sphere. Edinburgh Instruments offers a demountable integrating sphere for quantum yield and reflection measurements of solutions or solid samples. The integrating sphere fits directly into the sample chamber and is supplied with a cuvette holder and a mount for powder samples.
FLS1000 FS5